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Synthesis and characterization of inherently flame‐retardant and anti‐dripping thermoplastic poly(imides‐urethane)s
Author(s) -
Tang Qiheng,
Song Yun,
He Jiyu,
Yang Rongjie
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.40801
Subject(s) - fire retardant , limiting oxygen index , cone calorimeter , materials science , pyromellitic dianhydride , thermoplastic , polyurethane , thermoplastic polyurethane , ultimate tensile strength , molar mass , polymer chemistry , composite material , thermogravimetric analysis , char , chemical engineering , polyimide , pyrolysis , polymer , layer (electronics) , elastomer , engineering
A series of thermoplastic poly(imide‐urethane)s (TPIUs), based on 4,4′‐diphenylmethane diisocyanate (MDI) and pyromellitic anhydride (PMDA) as hard segments and poly(tetrahydrofuran) (PTMG) as soft segments, has been prepared by a two‐step polymerization process. The objective of this study is to prepare a type of intrinsically flame‐retardant polyurethane by incorporating PMDA as a flame retardant in the main chains. The thermal behavior and flame retardancies of the TPIUs have been characterized by thermal gravimetric (TG) analysis and limiting oxygen index (LOI), UL‐94 vertical burning, cone calorimeter tests. The results indicate that the TPIUs display outstanding performance. The temperature at 5% mass loss ( T 5% ) and LOI value increase with the hard‐segment contents, while the total heat released (THR) and peak heat release rate (p‐HRR) show the opposite trend. Furthermore, the T 5% of TPIU211 (molar ratio: MDI : PTMG : PMDA = 2 : 1 : 1) is 33.2°C higher than that of the conventional thermoplastic polyurethane TPU211 (molar ratio: MDI : PTMG : 1,4‐butanediol = 2 : 1 : 1), and the THR and p‐HRR of TPIU211 are 14.62% and 64.02% lower than the respective parameters of TPU211. In addition, UL‐94 vertical burning tests show that the TPIUs exhibit excellent antidripping effects. The ultimate tensile strengths of the TPIUs reached 23.1−37.6 MPa with increasing hard segment contents, which meets the requirement of mechanical properties with regard to practical use. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40801.